1. Technical Field
The present invention relates generally to housings for devises such as power tools, including rotatable drills, power screwdrivers and cutting tools. More particularly, the present invention relates to a housing having an overmold portion in which the overmold portion performs an auxiliary function.
2. Discussion
Modern manufactures of power tools typically seek to provide powerful and robust tools that are both ergonomically configured and which offer exceptionally high value at a relatively inexpensive price. Often times, however, the goal of a robust, ergonomic configuration seems to be at odds with the offering of the tool at a relatively inexpensive price as additional processes, such as overmolding, or a multiplicity of parts that do not appear to add significant value, such as vibration isolators and seals, are required.
The overmolding of the grip of a hand tool is known in the art for purposes of reducing the transmission of vibration to the user""s hand. In these situations, the outer surface of the grip of the tool is overmolded with a resilient material; the overmolded portion tends to damp the vibrations that are transmitted between the housing of the tool and the user""s hand. The overmolded portion does not effect the operation of the tool per se, and as such, the use of overmolding tends to be limited to a relatively small area on the exterior of the tool so as to minimize the cost of the tool. More specifically, the overmolding operation is typically employed in a non-functional manner which adds cost to the article of manufacture without adding a commensurate amount of value.
While parts, such as isolators and even seals, may be necessary for the proper operation of the power tool, their discrete nature nonetheless increases the cost of the power tool, both in terms of materials and in assembly labor. Furthermore, the proliferation of component parts is known to have a detrimental on defect rates and warranty costs. Accordingly, there remains a need in the art for a functional overmold which adds value to the article of manufacture in an amount commensurate with its cost.
In one preferred form, the present invention provides an article having a first structure and a second structure. The first structure includes a structural portion and an overmold portion, which is formed from a resilient material and molded onto the structural portion. The overmold portion is configured to perform an auxiliary function, such as creating a seal portion that is configured to sealing engage the second structure, an isolator portion that is configured to contact the second structure and dampen vibrations that are transmitted thereto and/or an auxiliary gripping surface.